Treating partial oxidation products



PM .Im. 31, 1933 UNITED STATES A ENT? OFFICE I J'OBIPE HIDY 35.115, 01' IITTBFUBGH, PENNSYLVANIA, ASSIGNOB 1'0 (memo! P. BYBNES, TRUSTEE, OF SEWICKLEY, PENNSYLVANIA ramme mm oxnwrron rnonucrs 80 Drawing. Original application fled Kay 18, 1888 Serial No. 639,986. Divided and thil' application ma Jane 19, 1929 This application is a division of my copending application Serial No. 639,986,.now Patent No. 1,721,959 of J uly 23, 1929.

The present divisional application relates 5 to fractioning a partial oxidation roduct containing oxygen derivatives of a iphatic.

hydrocarbons, separating the fractions and further oxidizing a fraction or a port on of a fraction thus separated; and to further processes not claimed in and divisible from.

my Patent No. 1,721,959.

In my copending applications Serial No."

272,567, filed January 22, 1919; Serial No.

435,355, filed January 6, 1921, and others, I have described methods for the vapor phase partial oxidation of hydrocarbons, including petroleum shale oil, the low temperature distillation of coal and the like, consisting mainly of aliphatic h drocarbons.

In. such methods, t e liquid hydrocarbons are vaporized, mixed with a regulated roportion of oxygen, usuall in the form 0 air,

clud'es the following metals ':titanium,

vanadium, chromium, manganese, zirconium,

niobium, molybdenum, tantalum, tungsten and uranium.

As set forth in my copending application, Serial No. 435,355,t e vapor mixture may be and preferably is passed'over a plurality of layers, air or oxygen bein 'supphed between some or all of the layers. he air proportion O. and 500 (3., depending upon the products developed since the ate of this diagram. The class in- Serial No. 372,218.

is varied accordin to the catalyst used, the temperature and t e speed-ofthe current. The more active the catalyst, the nearer the air can approach the theoretical amount; andthe same as to temperature. Steam may also be supplied in regulated proportions. The temperature is below that of continuous'selfsustained combustion and will vary according to the hydrocarbon treated, the catalyst used, etc.; and if a predominance of aldehyde is desired, will usually be lower than that where a predominance of aldehyde fatty acids is desired. 4

The condensed product of this treatment will contain alcohols," aldehydes, and oxygenated acids in varying proportions, .dcpendin upon the conditions of the process the hy rocarbon treated, etc. As the liquid hydrocarbon treated contains hydrocarbons o varying molecular weight, the product will contain alcohols, aldehydes andacids of varying molecular weights. The aldehydes are probably in partmonoaldehydes and in part dialdehydes.

My present invention is designed to further treat such product of my mam process and to further oxidize the constituents thereof, or portions of them, to give a better type or class of products for industrial uses, such as 'soa ma in etc. When the original product is saponi ed in the ordinary way, the soaps produced are dark in color and have a peculiar odor. The color and odor are both greatly improved by the further oxidation treatment of my present invention. This application is 5 in part a continuation of my copending a plication, gerial No. 281,124, filed March i919 now atent No. 1,697,653 of January-1,

The acids of my main process, particularly in the higher boiling ranges, are aldehydic in character and the congeneric oil (the non-saponifiable oil) of the product consists almost completely of bodies containing oxygen. Hence the condensedproductisamen- P acids of able to further oxidation which my present invention is designed to accomplish.

Under the preferred form of my present rocess I. propose to oxidize the oxygenated var ing molecular weights to dibasic acids, and t e aldehydes of varyin molecular weights to ordinary monobas1c fatty acids or to dibasic acids (depending upon whether the aldehyde is a monoor a ialdehyde) If the reaction is continued sufproduct distilling under 200 C. and'apply the further rocess to the remainder.

some cases ma distil up to 300 C. or higher and use t e remainder for further oxidation.

' The further oxidation may be carried out in several was and I may use chemical oxidation me ods, such for exam 10 as set forth in the following three examp es:

I. This is the chromic acid oxi ation and may becarried out by the use of a solvent (for both the product and the chromic acid) or without such solvent. In the latter case, a sus 'on of the organic product, and a water solution of the chromic acid, is used.

An example of the suspension method is as follows: A sam leconsisting of 100 c. c. of theventire con ensed oxidation product made by the catalytic air oxidation of unrefined spindle oil (mid-continent), and containing approximately of organic acids, was treated in a suspension of one to four sulphuric acid with a half saturated solution of chromic acid in' water. The suspension of oil oxidation product was maintained by violent mechanical agitation and the chromic acid solution was run in slowly, care being taken that the temperature did not rise above 40 C. After the chromic treatment, when a test for free chromic acid was obtained which persisted for one hour, the reaction was stopped, the organic product separated, washed and tested for the qualit and amount of fatty acids. It was found t at the fatty acids had risen from 30% to 48%, and that only a very small amount of aldehydic substances were left. The soaps, even when made by boiling with caustic potash or caustic soda solution were of a yellowish cream color, in strong contrast to the dark brown soaps formed by the original catalytic oxidatlon acids.

In another trial with the same catalytic oxidation product, but by the use of 200 c. c. of glacial acetic acid as a solvent and a chromemes mic acid solution made by mixing one volume of a saturated water solution of chromic acid with four volumes of glacial acetic acid, and a temperature of 27 to 32 C., the other conditions as to agitation, addition of oxidant, etc., being the same as in the preceding example, the acid content was brought up to 59% and the acids were of even better quality than those obtained in the foregoing ex erimeut.

For large scale operation, the rst or suspension method Wlll probably prove more economical. Since it is not at all difficult to work a cyclic electrolytic regeneration recovery process for the chromic acid, this method of making fatty'acids has great possibilities.

II. ThlS method of carrying out the chemical oxidation of the product obtained by the first or catal 5c oxidation is based on the oxidizing actlon of chlorine, and further, on the direction of hypochlorous acid decomposition towards the formation of hydrochloric acid and oxygen. v

When chlorine gas is assed into water, hypochlorous acid ,(HO l) is one of the products.

' momn nownocl' products on the However this mixture of n re cm the original substances, chlorine and water. In the presence of certain catalysts, the hypochlorous acid (HOCl) can be made to decompose as follows:

2HOC1 catalyst(CoC$l etc.) 2HC1+ O,

This reaction applied to calcium hypochlorite in water solution is the well known La Voisite process for makin oxygen.

I have applied this reaction to a water or dilute acid suspension of the catalytic oxidation mixture to accomplish the same-purpose as that of Method I.

' ht hand side of the equation can react to 9-5 The followin example will show how this I reaction is app led.

A mixture was made of -the following proportions: c. c. spindle oil catalytic oxide mixture, 500 c. c. water, 100 c. c. 2% cobalt chloride solution, and 50 c. c. concentrated hydrochloric acid solution.

A vigorous mechanical stirrin brought about a good suspension of the oxi ized oil in the water solution. A slow stream of chlorine gas was passed into the suspension for six hours at 95 0. Some cobalt soaps se arated out under these conditions. Whi e the character of-the acids recovered from this mixture was not as good as in Method I, the acid has been increased to approximately 50%, (some aldeh de bodies were still present or had been ormed because of incomplete oxidation). This method can be easily used to increase the acid content of a catalytic air oxidation mixture, sincethe chlorine is available and cheap.

III. This method is based on the properties, physical and chemical, of the oxides of nitrogen andof nitric and nitrous acids. N1- tric acid itself is a violent oxidizing a nt. The oxides of nitr n, nitric oxide O nitrogen dioxide (N are soluble in mtrlc acid and in nitric acid water solutions down to certain concentrations. Nitric acid readily breaks down, these oxides being the main products. Now .the lower of these oxides (NO) readil takes on olxlygen from the air going up to t e dioxide The dioxide is an energetic oxidizing a nt.

Having, as a medium, d1 ute nitric acid to act as a solvent for these oxides and also to provide a menstruum for the suspension of the organic material to be oxidized, we have all the conditions for what is really an air oxidation of the catalytic oxidation mlxture. The nitric acid and the nitrogen oxides function about the same as they do in the lead chamber process for making sulphuric acid.

v oxidation can This method, then, consists in making a suspension of the organic material in the nitric acid solution of whatever concentration selected and at temperatures usually rather low for the best results; then by bubbling air through thea 'tated suspension, the desired carried almost to completion.

The following example will serveto illustrate the application of this method. A mixture was made up of the following proportions: 300 c. c. catalytic oxidation mixture made from a 50: 50 gas oil-wax distillate blend and 500 c. c. nitric acid solution, 22%.

This mixture was violently a itated by a mechanical stirring device and air bubbled in violently for twelve hours, the temperature not being allowed to rise above 50 0., being kept most of the time at 45 C. The oxidation mixture gradually changed in color from the original .dark brown to a light brick red. When the oxidation is complete, the greater part of the or anic acids will sink in water.

11 this exam e, the bottom layer, representing 80% of t e total, was completely saponifiable and the top layer, representing 20% of the product, was 80% saponifiable. This shows that practically 96% 'of'the material fed into the original catalytic air oxidizer had been acted on by the oxidation, as the action on the original hydrocarbons under these mild oxidizing conditions isvery slight.

I propose to carry out this'reaction on a large scale by blowing air successively through a long connected series of such mixtures in properly arranged apparatus. The

.small amount of nitro en oxides escaping from the last vessel of t e train can be easily absorbed in an alkali tower and the tartric and nitrous acidsrecovered or the Gay-Lussac tower method used by the manufacturers of sulphuric acid may be used for this recov- I may also add certain oxides to the acid in order to aid in .the above reaction, such as vanadium 'pentoxide, molybdenum trioxide, etc.

In all the above methods, it should be noted that a good total recovery is obtainedfrom' 85-to 95% being the usual practice.

I may also in each of the foregoing methods remove the last of the aldehydic bodies at the end of the second oxidation by long agitation of the suspended acids in a rather concentrated sodium bisulphite solution.

Final purification of the ordinary vacuum or vacuum-steam distillation methods may be applied to the products made by any of the above schemes.

While I may chemically oxidize the liquid partial oxidation or partial combustion product in the liquid phase, as above described in the typical methods set forth, I may, especially for certain purposes, vaporize said original partial oxidation products of my main process, mix the vapor with oxygen (preferably in the form of air) and sub ect the mixture to a catalytic partial oxidation, using steam also in some cases, as set forth in my copending ap lication Serial No. 281,124, filed March 1919, new Patent No. 1,697,653 of January 1, 1929. In this step, which is generally the same as the main original process step, a catalyst may or may not be used,

though I prefer to employ it in the hot reaction zone. In this step, the carbon compounds of the ori 'nal product are further oxidized, the alde ydes being largely converted into acids. a

The multiple-screen system of my copending application Serial No. 435,355 may be advantageously employed in this further oxidation step, and as in the original process, the air 'is regulated and thecatalyst 'maintained within a definite range of temperature, depending upon the average molecular weight of the mixture treated, which, in turn, depends upon the oil fraction treated in the main process. Here again, the temperature is preferably kept below that of continuous self-sustained combustion, though such may occur and completely oxidize a part of the vaptlr mixture. This, however, lowers the 1e y The proportions of air and aldehyde vapor,

whetherof the whole product or a fraction ing upon the fraction originally trea san as group as those used in the original process. ried out to produce arpredommance o aldehydes, the temperature being ke t somewhat lower than that for producin al ehyde fatty acids, for example, aroun 250 C. for Pennsylvania kerosene.

I Wlll now describe aspecific example of my process using the above apparatus:

Conditions (A) Catalyst: Uranyl molybdate on as bestos, held between parallel screems, the active material packed in a disk-shaped space 4 c. diameter and 1.25 0. thick.

(B) Aldeh de mixture treated: A mixture of alip atic aldehydes made from Pennsylvania petroleum kerosene having the following composition:

In addition, from the water-absorbing system, aldehyde fatty acids soluble in waterare recovered in the form of their calcium salts, amounting to 2.64 grams.

In using this vapor phase oxidation meth-.

ed for the ori 'na products containing al-' cohol and alde ydes and aldeh (ii acids, i515 li ter rtion or,- portions 0 e origin pfd duct ay be distilled ofi, before the further oxidation step is applied to the heavier portions.

The tem ratures used in the oxidation steps vary om 230 C. to 500 0., de udthe amount of air, etc.

I consider myself. the first to discover a practical process for treating mixtures of aliphatic aldehydes of varying molecular weight and converting them into the corresponding acids; and also the first to oxidize a mixture containing alcohols and aldehydes and convert portions of the aldehydes into acids.

In the chemical oxidation step, true fatty acids are produced along with dibasic acids. By the term air in my claims, I intend to cover air or oxygen or any gas mixture containing free oxygen.

he original process is preferabl car-,

tions of ring the A catalyst may or may not be used in the vapor phase oxidation step; the apparatus used may be widely varied, the chemical oxi- .dant used maybe changed and other cha eparting from my mthis case as such are covered in my copending application Serial No. 549,567, filed April 4, 1922, for method of making dib'asic acids and compounds thereof, now Patent No. 1,721,958 of July 23, 1929.

I I claim: I

r 1. The method of treating: partial oxidation mixture containing hy ocarbon oxygen derivatives of different molecular wei ts, consisting in fractioning the same into' actions of difi'erent average molecular weight, each containing oxygen derivatives of di erent molecular weights, separating the fractions and then further oxidizing a fraction or part thereof.

2. The method of treatingra partial oxidation mixture containing hy ocarbon oxygen derivatives of different molecular wei ts, consisting in fractioning the same into c ifierent average molecular wflight, each containing oxygen derivatives of erent molecular weights, separating the fractions and then further oxidizing at least a portion ofafraction.

3. The method of treatin' a partial oxida:

tion mixture containing hy rocarben oxygen derivatives of difierent molecular weig ts, consisting in fractioning the same, se arating the fractions and then further oxi ing at; cast a portion of a fraction by mixing the same with air and passing it through a hot reaction zone at'a reactive temperature.

4. The method of treatin apartial oxidation mixture containing hy rocarbon oxygen derivatives of difierent molecular weig ts, consistin in fractioning the same, separatactions, vaporizing. at least a portion of a fraction, and mixing the same with an oxygen-containing gas and passing it through a hot reaction zone at a reactive temperature.

5. The method of treating a partial oxidation mixture containin hydrocarbon oxygen derivatives of di erent molecuar weights, consisting in fractionin the same, separatin the fractions and then rther oxidizing at east a rtion of a fraction by mixin the same wit air and passing it through a ct reaction zone at a reactive temperature in the presence of a catalyst.

6. The method of treatin a partial oxide tion mixture containing hy rocarbon oxygen derivatives of different molecular weig ts, consistin in fractioning the same, separatlng the fractions, vaporizing at least a portion of a fraction, and mixing the same with an oxygen-containing gas and passing it of difierent molecular weights, separatin the fractions, and then further oxidizing at east a portion of a fraction by adding an oxidizing reagent thereto while in the liquid phase.

In testimony whereof I have hereunto set my hand.

JOSEPH HIDY JAMES. 

